public class Test01 {
    public static void main(String[] args) {
        Cat cat = new Cat();
        cat.move();
        Bird bird = new Bird();
        bird.move();
        Animal a1 = new Cat();
        Animal a2 = new Bird();
        Animal a3 = new Cat();
        Cat c = (Cat)a3;
        c.CatchMouse();
        Animal a4 = new Bird();
        Cat c1 = (Cat)a4;
        c1.CatchMouse();
    }
}
